<!DOCTYPE html>
<html>
  <head>
    <title>计算器</title>
     <meta charset="utf-8">
     <meta  name="viewport" content="width=device-width" /> 
  </head>
	<body>
		<input id="num1" /> * <input id="num2" />
		<button onclick="jiSuan()" /> = </button>
		<input id="num3" />

	<script>
		function jiSuan(){
			num3.value=num1.value*num2.value;
		}
	</script>
	</body>
</html>